oa.ctrl.rf.sizeComparison = {
/**
 * Evaluate the user's answers for a sizeComparison
 * 
 * @author Linda Eckardt
 * 
 * @param {array} answer The user's answer
 * @param {array} answer  The user's answer
 */
evaluate: function( answer) {
  var correct = oa.ctrl.rf.sizeComparison.getSortedNumbers();
      result = [];
  
  for (var i = 0; i < answer.length; i++)
    if (answer[i] < correct[i] || answer[i] > correct[i])
      result.push(i);
  if (result.length == 0) {
    oa.view.showSmilingAri();
    if (oa.attemptCounter <= 1) oa.correctAnswerCounter += 1;
  } else {
    oa.view.showDisappointedAri();
    oa.attemptCounter += 1;
  }
  percentageCorrect = (oa.learningUnitProblemCounter<=0) ? 0 : Math.floor( oa.correctAnswerCounter / oa.learningUnitProblemCounter * 100);
  oa.view.showPercentageCorrect( percentageCorrect);  
  return result;
},

/**
 * Sort current problem numbers numerical ascending
 * 
 * @author Linda Eckardt
 * 
 * @returns {array} The numbers in (correct) sorted order
 */
getSortedNumbers: function() {
  var sorted = oa.currentProblem.operands.slice();
  if (oa.currentProblem.type.numberType != NumberTypeEL.Fraction)
    sorted.sort(function(a, b) {return a - b;});
  else
    sorted.sort(function(a, b) {return a[0]/a[1] - b[0]/b[1];});
  return sorted;
}

};